The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 07, 1997
Filed:
Aug. 02, 1996
Applicant:
Inventor:
Gary J Sgrignoli, Mt. Prospect, IL (US);
Assignee:
Zenith Electronics Corporation, Glenview, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03D / ;
U.S. Cl.
CPC ...
329357 ; 329360 ; 375317 ; 375321 ; 455204 ; 455214 ;
Abstract
A polarity detection circuit for an FPLL demodulated signal including a small DC pilot recovers the DC pilot by determining the DC levels of the demodulated output signals both with and without the DC pilot. A zero carrier condition is created for determining the DC level of the output signal without the DC pilot. The two DC levels are subtracted and limited and the polarity of the recovered DC pilot is used to control the operation of a polarity inverter to assure that the output signal has a desired polarity.